The current invention addresses the problem of long lasting accurate ink marks applied to the ocular surface as needed for the correction of astigmatism.
In the field of refractive surgery there exists a need to place ink marks on the eye in order to orient the treatment of astigmatism. Astigmatism is a condition where the shape of the cornea bends light to more than one focal point causing a blurred image upon the retina. Astigmatism caused by the cornea is described as corneal astigmatism or corneal cylinder. It can be treated by altering the shape of the corneal through incisions or laser means so the light entering the eye is refracted to one focal point. Alternatively, in the field of cataract surgery, the corneal astigmatism can be balanced by an intraocular toric lens implant that has a curved surface that counterbalances the corneal astigmatism. Regardless of the means of treatment of astigmatism, the eye has to be marked before surgery in order to properly position the treatment of the astigmatism.
The current means of marking the eye generally involves the use of metal corneal markers. In most cases the metal marker has projections that will touch the cornea or sclera. Ink from a sterile surgical marker is transferred from the ink marker to the projections of a sterilized metal marker. This thin layer of ink is then transferred to the eye by compressing the metal marker projections against the anesthetized cornea. All markers currently used suffer from issues of inadequate ink transfer to the eye surface principally due to the fact that only a thin layer of ink is being transferred to an ocular surface and that wet from the ocular tear film. The ink marks so placed are blinked off within minutes. Because the marks are so short lived they must be placed immediately before the onset of surgery.
All patients are now required to have the operative site marked with a surgical marker before being brought into the operating room. A review of the general steps used to mark a patients eye before surgery will help better understand the full extent of the challenges facing the surgeon and patient.
Sequence Option 1—Marking in the Operating Room
                1. After the patient has been sedated and has been marked over the operative eye brow, they are brought into the operating room on a stretcher reclined at about 30-45 degrees.        2. The patient is then asked to sit up as straight as possible for the surgeon to mark the eye with an inked sterile metal marker that has marking fins rotated to the desired astigmatic axis.        3. The patient then lies down and is prepped and draped for surgery with marks in the proper position for surgery.        
It is well known that the position of the eye rotates or undergoes cyclotorsion when the patient moves from a vertical or sitting position to a lying or supine position. Errors induced by supine marking can be up to 20 degrees which results in a dramatic reduction in the effectiveness of the astigmatism correction. Consequently, the eye must be marked with the patient in the sitting or vertical position since this is the normal position of use for the eyes. This requirement conflicts with the typical operating room sequence of having the patient lying down, prepped, draped and ready for the surgeon before the surgeon enters the operating room. The need for the patient to be marked in the sitting position by the surgeon delays the normal prep sequence for surgery. An alternative sequence is to have the patient pre-marked in another patient preparation area where oral sedation is administered. The pre-marking is done with a surgical ink marker applied to the area where the cornea meets the sclera. These markers leave a lasting residue of ink not found with the thin film of ink applied with sterile metal markers. The sequence in these cases is as follows:
Sequence Option 2—Marking in Preoperative Area:
                1. Patient is asked to sit up straight and fixate on a distant object.        2. The surgical marker is applied to the eye in the horizontal and, when possible, vertical meridians. These marks serve as reference marks to identify the eye position when the patient is upright.        3. Once the remainder of the patient preparation is accomplished the patient is moved to the operating room where they are placed in the supine position and then prepped and draped for surgery.        4. The surgeon begins by identifying the previously placed reference surgical marker marks that were placed on the eye when the patient was upright.        5. A sterile metal marker that has been inked is used with the previously placed reference marks to properly place the astigmatic axis marks of the sterilized metal marker.        
This sequence is more efficient because surgeons are required now to mark the patient's brow over the eye having surgery prior to being moved to the operating room. Because every patient gets marked with a surgical marker over the brow, it is convenient for the surgeon to add marks on the eye at the same time. Metal markers retain only a thin film of ink that is blinked off within a few minutes and consequently, they cannot be used for marking outside of the operating room.
Clearly the above system to mark the eye for the treatment of astigmatism is complex and creates limitations as to the accuracy of the marks placed, how the procedure is performed and how the patient flow is achieved. In order to alleviate the above disadvantages the current invention is presented herein.
The advantages of an eye marking device and tip, with a pre-inked, sterile, optionally disposable marking apparatus that is positioned using an automatic electrical positional detection system can be better appreciated better through the accompanying illustrations and description below.